Upgrade subject to access all content
Regions of DNA such as origins of replication and gene promoters are usually AT-rich, meaning that they have more A-T base-pairs than G-C base-pairs in their sequences.
What is the best explanation for this observation?
A-T base pairs interact more readily with DNA-binding proteins than G-C base pairs do.
More mutations to A or T occur than to G or C.
A-T base pairs have two hydrogen bonds while G-C base pairs have three.
DNA repair is biased toward A-T base pairs.